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<p>The QExtensionFactory class allows you to create a factory that is able to make instances of custom extensions in Qt Designer. <a href="#details">More...</a></p>
<pre> #include &lt;QExtensionFactory&gt;</pre><p>Inherits <a href="qobject.html">QObject</a> and <a href="qabstractextensionfactory.html">QAbstractExtensionFactory</a>.</p>
<ul>
<li><a href="qextensionfactory-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="public-functions"></a>
<h3>Public Functions</h3>
<ul>
<li><div class="fn"/><b><a href="qextensionfactory.html#QExtensionFactory">QExtensionFactory</a></b> ( QExtensionManager * <i>parent</i> = 0 )</li>
<li><div class="fn"/>virtual QObject * <b><a href="qextensionfactory.html#extension">extension</a></b> ( QObject * <i>object</i>, const QString &amp; <i>iid</i> ) const</li>
<li><div class="fn"/>QExtensionManager * <b><a href="qextensionfactory.html#extensionManager">extensionManager</a></b> () const</li>
</ul>
<ul>
<li><div class="fn"/>29 public functions inherited from <a href="qobject.html#public-functions">QObject</a></li>
<li><div class="fn"/>1 public function inherited from <a href="qabstractextensionfactory.html#public-functions">QAbstractExtensionFactory</a></li>
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<a name="protected-functions"></a>
<h3>Protected Functions</h3>
<ul>
<li><div class="fn"/>virtual QObject * <b><a href="qextensionfactory.html#createExtension">createExtension</a></b> ( QObject * <i>object</i>, const QString &amp; <i>iid</i>, QObject * <i>parent</i> ) const</li>
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<ul>
<li><div class="fn"/>7 protected functions inherited from <a href="qobject.html#protected-functions">QObject</a></li>
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<h3>Additional Inherited Members</h3>
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<li><div class="fn"/>1 property inherited from <a href="qobject.html#properties">QObject</a></li>
<li><div class="fn"/>1 public slot inherited from <a href="qobject.html#public-slots">QObject</a></li>
<li><div class="fn"/>1 signal inherited from <a href="qobject.html#signals">QObject</a></li>
<li><div class="fn"/>5 static public members inherited from <a href="qobject.html#static-public-members">QObject</a></li>
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<a name="details"></a>
<hr />
<h2>Detailed Description</h2>
<p>The QExtensionFactory class allows you to create a factory that is able to make instances of custom extensions in Qt Designer.</p>
<p>In <i>Qt Designer</i> the extensions are not created until they are required. For that reason, when implementing a custom extension, you must also create a QExtensionFactory, i.e&#x2e; a class that is able to make an instance of your extension, and register it using <i>Qt Designer</i>'s <a href="qextensionmanager.html">extension manager</a>.</p>
<p>The <a href="qextensionmanager.html">QExtensionManager</a> class provides extension management facilities for Qt Designer. When an extension is required, Qt Designer's <a href="qextensionmanager.html">extension manager</a> will run through all its registered factories calling <a href="qextensionfactory.html#createExtension">QExtensionFactory::createExtension</a>() for each until the first one that is able to create a requested extension for the selected object, is found. This factory will then make an instance of the extension.</p>
<p>There are four available types of extensions in Qt Designer: <a href="qdesignercontainerextension.html">QDesignerContainerExtension</a> , <a href="qdesignermembersheetextension.html">QDesignerMemberSheetExtension</a>, <a href="qdesignerpropertysheetextension.html">QDesignerPropertySheetExtension</a> and <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a>. Qt Designer's behavior is the same whether the requested extension is associated with a multi page container, a member sheet, a property sheet or a task menu.</p>
<p>You can either create a new QExtensionFactory and reimplement the <a href="qextensionfactory.html#createExtension">QExtensionFactory::createExtension</a>() function. For example:</p>
<pre> QObject *ANewExtensionFactory::createExtension(QObject *object,
         const QString &amp;iid, QObject *parent) const
 {
     if (iid != Q_TYPEID(QDesignerContainerExtension))
         return 0;

     if (MyCustomWidget *widget = qobject_cast&lt;MyCustomWidget*&gt;
            (object))
         return new MyContainerExtension(widget, parent);

     return 0;
 }</pre>
<p>Or you can use an existing factory, expanding the <a href="qextensionfactory.html#createExtension">QExtensionFactory::createExtension</a>() function to make the factory able to create your extension as well. For example:</p>
<pre> QObject *AGeneralExtensionFactory::createExtension(QObject *object,
         const QString &amp;iid, QObject *parent) const
 {
     MyCustomWidget *widget = qobject_cast&lt;MyCustomWidget*&gt;(object);

     if (widget &amp;&amp; (iid == Q_TYPEID(QDesignerTaskMenuExtension))) {
         return new MyTaskMenuExtension(widget, parent);

     } else if (widget &amp;&amp; (iid == Q_TYPEID(QDesignerContainerExtension))) {
         return new MyContainerExtension(widget, parent);

     } else {
         return 0;
     }
 }</pre>
<p>For a complete example using the QExtensionFactory class, see the <a href="designer-taskmenuextension.html">Task Menu Extension example</a>. The example shows how to create a custom widget plugin for Qt Designer, and how to to use the <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> class to add custom items to Qt Designer's task menu.</p>
<p>See also <a href="qextensionmanager.html">QExtensionManager</a> and <a href="qabstractextensionfactory.html">QAbstractExtensionFactory</a>.</p>
<hr />
<h2>Member Function Documentation</h2>
<h3 class="fn"><a name="QExtensionFactory"></a>QExtensionFactory::QExtensionFactory ( <a href="qextensionmanager.html">QExtensionManager</a> * <i>parent</i> = 0 )</h3>
<p>Constructs an extension factory with the given <i>parent</i>.</p>
<h3 class="fn"><a name="createExtension"></a><a href="qobject.html">QObject</a> * QExtensionFactory::createExtension ( <a href="qobject.html">QObject</a> * <i>object</i>, const <a href="qstring.html">QString</a> &amp; <i>iid</i>, <a href="qobject.html">QObject</a> * <i>parent</i> ) const&nbsp;&nbsp;<tt> [virtual protected]</tt></h3>
<p>Creates an extension specified by <i>iid</i> for the given <i>object</i>. The extension object is created as a child of the specified <i>parent</i>.</p>
<p>See also <a href="qextensionfactory.html#extension">extension</a>().</p>
<h3 class="fn"><a name="extension"></a><a href="qobject.html">QObject</a> * QExtensionFactory::extension ( <a href="qobject.html">QObject</a> * <i>object</i>, const <a href="qstring.html">QString</a> &amp; <i>iid</i> ) const&nbsp;&nbsp;<tt> [virtual]</tt></h3>
<p>Returns the extension specified by <i>iid</i> for the given <i>object</i>.</p>
<p>Reimplemented from <a href="qabstractextensionfactory.html#extension">QAbstractExtensionFactory</a>.</p>
<p>See also <a href="qextensionfactory.html#createExtension">createExtension</a>().</p>
<h3 class="fn"><a name="extensionManager"></a><a href="qextensionmanager.html">QExtensionManager</a> * QExtensionFactory::extensionManager () const</h3>
<p>Returns the extension manager for the extension factory.</p>
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